build-docker.yml

# Build and publish a Docker image.
#
# Assumed to run as a subworkflow of .github/workflows/release.yml; specifically, as a local
# artifacts job within `cargo-dist`.
#
# Adapted from https://github.com/astral-sh/ty/blob/main/.github/workflows/build-docker.yml
name: "Build Docker image"

on:
  workflow_call:
    inputs:
      plan:
        required: true
        type: string
  pull_request:
    paths:
      - .github/workflows/build-docker.yml

env:
  PREK_BASE_IMG: ghcr.io/${{ github.repository_owner }}/prek

permissions:
  contents: read
  packages: write # zizmor: ignore[excessive-permissions]

jobs:
  docker-build:
    name: Build Docker image ghcr.io/j178/prek for ${{ matrix.platform }}
    runs-on: ubuntu-latest
    environment:
      name: release
    strategy:
      fail-fast: false
      matrix:
        platform:
          - linux/amd64
          - linux/arm64
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          persist-credentials: false

      - uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0

      - uses: docker/login-action@b45d80f862d83dbcd57f89517bcf500b2ab88fb2 # v4.0.0
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Check tag consistency
        if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
        env:
          TAG: ${{ inputs.plan != '' && fromJson(inputs.plan).announcement_tag || 'dry-run' }}
        run: |
          version=$(grep -m 1 "^version = " pyproject.toml | sed -e 's/version = "\(.*\)"/\1/g')
          if [ "${TAG}" != "v${version}" ]; then
            echo "The input tag does not match the version from pyproject.toml:" >&2
            echo "${TAG}" >&2
            echo "${version}" >&2
            exit 1
          else
            echo "Releasing ${version}"
          fi

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@030e881283bb7a6894de51c315a6bfe6a94e05cf # v6.0.0
        env:
          DOCKER_METADATA_ANNOTATIONS_LEVELS: index
        with:
          images: ${{ env.PREK_BASE_IMG }}
          # Defining this makes sure the org.opencontainers.image.version OCI label becomes the actual release version and not the branch name
          tags: |
            type=raw,value=dry-run,enable=${{ inputs.plan == '' || fromJson(inputs.plan).announcement_tag_is_implicit }}
            type=semver,pattern={{ raw }},value=${{ inputs.plan != '' && fromJson(inputs.plan).announcement_tag || 'dry-run' }},enable=${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}

      - name: Normalize Platform Pair (replace / with -)
        run: |
          platform=${{ matrix.platform }}
          echo "PLATFORM_TUPLE=${platform//\//-}" >> "$GITHUB_ENV"

      # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
      - name: Build and push by digest
        id: build
        uses: docker/build-push-action@d08e5c354a6adb9ed34480a06d141179aa583294 # v7.0.0
        with:
          context: .
          platforms: ${{ matrix.platform }}
          cache-from: type=gha,scope=prek-${{ env.PLATFORM_TUPLE }}
          cache-to: type=gha,mode=min,scope=prek-${{ env.PLATFORM_TUPLE }}
          labels: ${{ steps.meta.outputs.labels }}
          outputs: type=image,name=${{ env.PREK_BASE_IMG }},push-by-digest=true,name-canonical=true,push=${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}

      - name: Export digests
        env:
          digest: ${{ steps.build.outputs.digest }}
        run: |
          mkdir -p /tmp/digests
          touch "/tmp/digests/${digest#sha256:}"

      - name: Upload digests
        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
        with:
          name: digests-${{ env.PLATFORM_TUPLE }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  docker-publish:
    name: Publish Docker image (ghcr.io/j178/prek)
    runs-on: ubuntu-latest
    environment:
      name: release
    needs:
      - docker-build
    permissions:
      contents: read
      packages: write
      id-token: write
      attestations: write
    if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
    steps:
      - name: Download digests
        uses: actions/download-artifact@70fc10c6e5e1ce46ad2ea6f2b72d43f7d47b13c3 # v8.0.0
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

      - uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@030e881283bb7a6894de51c315a6bfe6a94e05cf # v6.0.0
        env:
          DOCKER_METADATA_ANNOTATIONS_LEVELS: index
        with:
          images: ${{ env.PREK_BASE_IMG }}
          # Order is on purpose such that the label org.opencontainers.image.version has the first pattern with the full version
          tags: |
            type=raw,value=${{ fromJson(inputs.plan).announcement_tag }}
            type=semver,pattern=v{{ major }}.{{ minor }},value=${{ fromJson(inputs.plan).announcement_tag }}

      - uses: docker/login-action@b45d80f862d83dbcd57f89517bcf500b2ab88fb2 # v4.0.0
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
      - name: Create manifest list and push
        working-directory: /tmp/digests
        # The jq command expands the docker/metadata json "tags" array entry to `-t tag1 -t tag2 ...` for each tag in the array
        # The printf will expand the base image with the `<PREK_BASE_IMG>@sha256:<sha256> ...` for each sha256 in the directory
        # The final command becomes `docker buildx imagetools create -t tag1 -t tag2 ... <PREK_BASE_IMG>@sha256:<sha256_1> <PREK_BASE_IMG>@sha256:<sha256_2> ...`
        run: |
          # shellcheck disable=SC2046
          readarray -t lines <<< "$DOCKER_METADATA_OUTPUT_ANNOTATIONS"; annotations=(); for line in "${lines[@]}"; do annotations+=(--annotation "$line"); done

          docker buildx imagetools create \
            "${annotations[@]}" \
            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf "${PREK_BASE_IMG}@sha256:%s " *)

      - name: Export manifest digest
        id: manifest-digest
        env:
          IMAGE: ${{ env.PREK_BASE_IMG }}
          VERSION: ${{ steps.meta.outputs.version }}
        run: |
          digest="$(
            docker buildx imagetools inspect \
              "${IMAGE}:${VERSION}" \
              --format '{{json .Manifest}}' \
            | jq -r '.digest'
          )"
          echo "digest=${digest}" >> "$GITHUB_OUTPUT"

      - name: Generate artifact attestation
        uses: actions/attest@59d89421af93a897026c735860bf21b6eb4f7b26 # v4.1.0
        with:
          subject-name: ${{ env.PREK_BASE_IMG }}
          subject-digest: ${{ steps.manifest-digest.outputs.digest }}